A couple tips for implementing the button:

1. You must include the URL of your Google+ page so the minimum value code would look like:

Example:

2. Similar to our Google +1 button, Google+ Follow badges come in multiple sizes; there is the option for a “Large version” that includes on page following. This button comes in a regular size and smaller size declared by either “badge” or “smallbadge”, respectively. There is also the buttons that solely link out to the brand page and those are “small”, “medium” and “large”.

does this actually have an effect on your rankings on google? I know it is to have someone add you on google+ which in turn will get you more people who will know of your presence, but I wonder if it has any direct correlation with rankings, or PR